If the user has input invalid values into range from and to, then there is no point checking any IPv6 VIPs to see if they fall in the range. None of them would be "in range" because the specified range is not even valid.
(cherry picked from commit 3707ffc4157408b498d3b84d64918d4e41b5a123)
DHCPV6 only check VIPs in range if range valid
If the user has input invalid values into range from and to, then there
is no point checking any IPv6 VIPs to see if they fall in the range.
None of them would be "in range" because the specified range is not even
valid.
(cherry picked from commit 3707ffc4157408b498d3b84d64918d4e41b5a123)